EP1220538A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical engine for front or rear screen SLM display systems
Assignee: Texas Instruments Inc
•
Filing: 2001-12-28
•
Granted: —
•
Expires: 2021-12-28
Abstract
Abstract An optical engine (15) for an SLM-type display system, which may be either a front or rear projection system (10, 20). The optical engine (15) provides for a high contrast, telecentric illumination angle to the SLM (33) without compromising brightness by vignetting due to offset in the pupil. The resulting offset pupil is converted to a telecentric, on-axis image by a relay path (34) between the SLM (33) and the projection lens (37). The relay path (34) places the image at an intermediate image plane accessible by a the projection lens (37), which permits the projection lens (37) to be telecentric without an offset pupil.
Inventors
- 👤 Michael T Davis
- 👤 Douglas W Anderson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 11:20
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3111; H04N9/3114; G; G02; G02B; G02B13/00; G02B13/22; G02B17/00; G02B17/08; G02B27/00; G02B27/18
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
145 words
An optical engine for use in an SLM-based display
system, comprising: a light source (including shaping optics, if any); an SLM for receiving light from the light source and for
reflecting an image; relay optics for receiving the image reflected from the
SLM, the relay path having: a first set of lenses that receives
the image from the SLM, a mirror that receives the image from
the first set of lenses, and a second set of lenses that
receives the image reflected from the mirror; wherein the first set of lenses is operable to receive the
image from the SLM as an offset pupil; wherein the second set of lenses is operable to place the
image at an intermediate image plane; and a projection lens operable to receive the image from the
intermediate image plane and to project the image to a display
image plane.
Claim 2
Dependent Claim
14 words
The optical engine of Claim 1, wherein the SLM is a
digital micromirror device.
Claim 3
Dependent Claim
27 words
The optical engine of Claim 1, wherein the SLM is a DMD
type SLM and wherein light from flat pixel elements is directed
away from the mirror.
Claim 4
Dependent Claim
25 words
The optical engine of Claim 1, wherein the SLM is a DMD
and light reflected from off pixel elements is directed away
from the mirror.
Claim 5
Dependent Claim
16 words
The optical engine of Claim 1, further comprising a
mask aperture at the intermediate image plane.
Claim 6
Dependent Claim
21 words
The optical engine of Claim 1, wherein the projection
lens is telecentric relative to the image at the intermediate
image plane.
Claim 7
Dependent Claim
18 words
The optical engine of Claim 1, further comprising a
color wheel for filtering light from the light source.
Claim 8
Independent Claim
144 words
A method of generating images for an SLM-type
projection display system, comprising the steps of: illuminating the SLM with a light source; generating an image, using the SLM, such that an image is
reflected from the SLM; receiving the image reflected from the SLM into a relay
path having the following elements: a first set of lenses that
receives the image from the SLM, a mirror that receives the
image from the first set of lenses, and a second set of lenses
that receives the image reflected from the mirror; such that the first set of lenses receives the image from
the SLM as an offset pupil; and such that the second set of lenses places the image at
an intermediate image plane; placing a projection lens in front of or inclusive to the
intermediate image plane; and projecting the image to a screen.
Claim 9
Dependent Claim
20 words
The method of Claim 8, wherein the placing step is
performed by placing the projection lens telecentric to the
image.
Claim 10
Dependent Claim
21 words
The method of Claim 9, wherein the telecentric
projection lens has any amount of offset to the relay axis,
including zero.
Claim 11
Dependent Claim
21 words
The method of Claim 8, wherein the illuminating step
is performed with an illumination angle that results in the
offset pupil.
Claim 12
Dependent Claim
21 words
The method of Claim 8, further comprising the step of
masking the border of the image at the intermediate image plane.
Claim 13
Dependent Claim
13 words
The method of Claim 8, wherein the SLM is a digital
micromirror device.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.